Powered by the sun

Indian workers emerge from underneath the solar panels at the Gujarat solar park at Charanka village of Patan district, some 250km from Ahmedabad. Electricity-hungry India will switch 26 million groundwater pumps for more efficient irrigation models powered by the sun.

Photo: AFP

India has a novel idea: Wean farmers from archaic power lines and expensive diesel fuel to run their water pumps with solar energy.

The government is looking to swap 26 million groundwater pumps for more efficient irrigation models powered by the sun. If successful, crop production could rise in India, where farms suffer from blackouts and volatile fuel costs. It would also save about US$6 billion a year in power and diesel subsidies.

“The potential is huge,” Tarun Kapoor, joint secretary at India’s Ministry of New and Renewable Energy, said in an interview. “Irrigation pumps may be the single largest application for solar in the country.”

Asia’s second-most populous nation will draw 100 billion rupees (US$1.6 billion) of investment in the next five years as the first 200,000 most easily replaceable pumps are switched to solar, the government estimates. That will relieve an overburdened power-transmission grid built mostly in the 1960s that’s prone to failures.

A risk in converting to solar pumps is that farmers may use excessive amounts of water because the devices have almost no operating costs. To avoid that, farmers must use water-saving drip irrigation in exchange for accepting subsidies to buy solar water pumps.

One who has already seen the benefits of switching over is O.V.R. Somasundaram, a 67-year-old who grows coconuts, nutmeg and cocoa in southern India. He invested two years ago in a solar pump from St. Peters, Missouri-based SunEdison.

SNAKE-BITE RISK

Somasundaram’s 75 acres of farmland in Coimbatore, Tamil Nadu, used to be dependent on electricity from the state, sometimes only available four hours a day from an antiquated grid. When the power came on, it was often at night, meaning workers risked snake bites as they wandered into dark fields.

“Crops need water,” he said in an interview in Chennai. “My crops would have failed if I hadn’t opted for a solar pump.”

Somasundaram now gets water when he needs it, throughout the year when the sun is out, and without the fuel costs of a diesel generator. He irrigates a third of his holdings with the system, which cost 400,000 rupees after 60 percent was subsidized.

‘BREAK LINK’

The new water reliability from a technology that moves away from older energy sources will allow him to plant an extra crop, black peppers. About 3,000 saplings are to be sowed by March.

Using fossil fuel-based power to pump well, canal and farm water also contributes to climate change, said Aaron Mandell, chairman of WaterFX, which sells solar desalination technology.

Let’s “break the link between carbon-based fuels and additional water production,” Mandell said. “The best way to do this is for the water industry to begin to take advantage of the cost reductions that have already occurred in renewable energy.”

The cost of photovoltaic panels that have slumped by half since 2010 and government subsidies mean the payback period of a solar pump system is one to four years, said Ajay Goel, chief executive officer of Tata Power Solar Systems Ltd, a panel maker and contractor that belongs to the US$100 billion Tata group, which has businesses including steel, software services and vehicles.